1. Field of the Invention
The invention relates generally to wind-power engineering and particularly to wind-driven electric plants, providing an optimal plant operation in emergency cases, preventing its destruction, under strong wind loads (e.g., in a storm, a tornado, a whirlwind), during an earthquake, under a threat of radioactive danger and so on.
2. Discussion of the Background
Wind-driven electric plants comprising a mast with a windwheel and a generator along with a control system are known in the art, e.g., SU 1612107, published Jul. 12, 1990. This known device provides protection of the plant structural components under strong wind loads. The windwheel blades turn to a feather position by means of blade rotation gear according to a control system command from the wind speed sensor under a storm wind, preventing blade destruction under the windwheel excessive acceleration because of a storm wind. A shortcoming of the known device is its inferior reliability, caused by blades remaining set to power takeoff angles when the blade rotation gear or the control system fails. When such failure occurs, a storm wind can rotate the windwheel to an unacceptably high speed, which can lead to the windwheel's destruction.
Also known in the art is a wind-driven electric plant containing a mast with a windwheel and a generator, a shielding chamber comprising a base, walls and a cover, and a mast transfer control device, connected with response sensors. (RU patent 55,887, Int. Class F03D 7/04, F03D 11/04, 27 Aug. 2006). The mast is attached at the shielding chamber base by a fastening-and-lifting device and attached to a mast transfer mechanism for stowing the mast in the shielding chamber or for setting the mast to operating position. This device is prior art.
The mast in the prior art is attached at the shielding chamber base by four braces, one of said braces is equipped with a rod, connected to a folding-spreading gear for the mast stowing in the shielding chamber or for its settling to the vertical operating position. The plant is equipped with an emergency response sensor and a folding-and-spreading gear automatic control system, connected with each other, for an automatic folding-and-spreading process.
One of the considerable shortcomings of the prior art is its inferior efficiency in emergency situations, caused by a number of structural constraints. Thus, a fastening-lifting device, realized as four braces, one of which is equipped with a rod, connected to a gear of a mast transfer mechanism, does not provide for quick and efficient stowing of the mast with the windmill in the shielding chamber or for restoration to the vertical operating position, since simultaneous manipulation of other braces is necessary for realizing the required operations. This increases a number of actuating devices and requires their synchronized actions, thus increasing the complexity of the device and increasing the execution time of operations. Moreover, mechanical damage to the device structural elements may occur during the mast stowing in the shielding chamber. It should be also mentioned that the known device can't provide continuous functioning in the case of a power supply failure under extreme weather conditions.
Abovementioned shortcomings considerably decrease the efficiency of the prior art device under extreme weather conditions.